let obj = {};
function changeValue(obj){
  obj.name = 'ConardLi';
  obj = {name:'code秘密花园'};
}
changeValue(obj);
console.log(obj.name); // ConardLi
console.log(obj);

const a={
    value:[3,2,1],
    valueOf:function(){
        //return this.value.pop()
       return this.value.pop();
    }
}

